Security readout for executives and security teams
Plain-English summary
A crafted prompt can cause a vulnerable Markdownify MCP server to make network requests and return responses. This may expose information available from the MCP host or its network. The issue affects mcp-markdownify-server versions before 1.0.0 and is rated high severity.
Executive priority
Treat as a high-priority remediation where vulnerable MCP servers process external content or have access to sensitive networks. Inventory immediately and upgrade promptly. Environments without the package are unaffected; isolated deployments have lower practical exposure but still require version verification.
Technical view
CVE-2025-5276 is an SSRF vulnerability in Markdownify.get(). When an MCP host accesses attacker-crafted content, webpage-to-markdown, bing-search-to-markdown, or youtube-to-markdown can request attacker-controlled URLs and read responses. The supplied CVSS 4.0 score is 8.2, emphasizing confidentiality impact without identified integrity or availability impact.
Likely exposure
Exposure exists where mcp-markdownify-server before 1.0.0 is installed and the affected tools can be invoked through untrusted prompts or content. Risk increases when the MCP host can reach sensitive services or data. The bundle does not identify specific deployment platforms or confirmed exposed instances.
Exploitation context
The attack requires active user interaction according to the supplied CVSS vector: an MCP host must access the crafted prompt. The record is not listed as KEV, and the supplied sources do not establish active exploitation campaigns. The vector records proof-of-concept exploit maturity, but prevalence is unknown.
Researcher notes
The bundle identifies CWE-918 and links the vulnerable source and remediation commit. It does not provide evidence of attacks in the wild, affected deployment counts, or confirmed data theft. Validate reachability and tool exposure defensively without sending requests toward sensitive services. The affected metadata says version "0," while the narrative consistently states versions before 1.0.0.
Mitigation direction
- Upgrade mcp-markdownify-server to version 1.0.0 or later.
- Review the linked vendor commit and release guidance before deployment.
- Restrict the MCP host's outbound network access to required destinations.
- Disable affected Markdownify tools until upgrading if untrusted content is processed.
- Limit the host's access to sensitive internal services and credentials.
Validation and detection
- Inventory installed mcp-markdownify-server versions and flag releases before 1.0.0.
- Confirm deployed instances use version 1.0.0 or later.
- Identify whether the three affected tools process untrusted prompts or content.
- Review outbound request logs for unexpected destinations or sensitive network access.
- Verify network controls prevent unnecessary access from the MCP host.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-918: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCloud metadata behavior lookup
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-5276 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P——snykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:P2.84snykVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:P
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://security.snyk.io/vuln/SNYK-JS-MCPMARKDOWNIFYSERVER-10249387CVE reference, snyk
- https://github.com/zcaceres/markdownify-mcp/commit/0284aa8f34d32c65e20d8cda2d429b7943c9af03CVE reference, snyk
- https://github.com/zcaceres/markdownify-mcp/blob/224cf89f0d58616d2a5522f60f184e8391d1c9e3/src/server.ts%23L20C17-L20C29CVE reference, snyk
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Server-Side Request Forgery (SSRF)
Server-Side Request Forgery (SSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.